Green Synthesis of Silk Sericin-Based Silver Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 487-490 ◽  
Author(s):  
Jia Li Ding ◽  
Wen Wu

Green synthesis of silver nanoparticles (AgNPs) using the silk sericin (SS) solution by in situ reduction at room temperature is reported. The effect of pH on the reduction reaction is studied by UV-Vis spectroscopy. The structure of the sericin-based silver nanoparticles is characterized by TEM. According to the TEM images, the average size of the silver nanoparticles is about 16 nm. The silver nanoparticles are highly dispersed and stable in silk sericin solution for monthes.

2012 ◽  
Vol 468-471 ◽  
pp. 1974-1977
Author(s):  
Wen Wu ◽  
Dong Sheng Wang

Semi-IPN hydrogels in which silk sericin (SS) chains were physically dispersed throughout dextran (Dex) gel networks were synthesized. Highly stable distributed silver nanoparticles have been prepared using these semi-IPN hydrogels as a carrier via in situ reduction of silver nitrate without the addition of any reducing agent. The resultant semi-IPN hydrogel-silver nanocomposites were characterized by X-ray diffraction (XRD). And the swelling behavior of the hydrogles was also studied.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1777 ◽  
Author(s):  
Md. Mahiuddin ◽  
Prianka Saha ◽  
Bungo Ochiai

A green synthesis of silver nanoparticles (AgNPs) was conducted using the stem extract of Piper chaba, which is a plant abundantly growing in South and Southeast Asia. The synthesis was carried out at different reaction conditions, i.e., reaction temperature, concentrations of the extract and silver nitrate, reaction time, and pH. The synthesized AgNPs were characterized by visual observation, ultraviolet–visible (UV-vis) spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The characterization results revealed that AgNPs were uniformly dispersed and exhibited a moderate size distribution. They were mostly spherical crystals with face-centered cubic structures and an average size of 19 nm. The FTIR spectroscopy and DLS analysis indicated that the phytochemicals capping the surface of AgNPs stabilize the dispersion through anionic repulsion. The synthesized AgNPs effectively catalyzed the reduction of 4-nitrophenol (4-NP) and degradation of methylene blue (MB) in the presence of sodium borohydride.


Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2383
Author(s):  
Majid Sharifi-Rad ◽  
Pawel Pohl ◽  
Francesco Epifano ◽  
José M. Álvarez-Suarez

Today, the green synthesis of metal nanoparticles is a promising strategy in material science and nanotechnology. In this research, silver nanoparticles (AgNPs) were synthesized through the high-efficient, cost-effective green and facile process, using the Astragalus tribuloides Delile. root extract as a bioreduction and capping agent at room temperature. UV–Vis spectroscopy was applied for the investigation of the reaction proceedings. To characterize the greenly synthesized AgNPs, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), and transmission electron microscopy (TEM) analyses were utilized. In addition, the total phenolics and flavonoids contents, antioxidant, antibacterial, and anti-inflammatory activities of the greenly synthesized AgNPs and the A. tribuloides root extract were evaluated. The results indicated that the AgNPs had spherical morphology and crystalline structure with the average size of 34.2 ± 8.0 nm. The total phenolics and flavonoids contents of the greenly synthesized AgNPs were lower than those for the A. tribuloides root extract. The resultant AgNPs exhibited the appropriate antioxidant activity (64%) as compared to that for the A. tribuloides root extract (47%). The antibacterial test approved the higher bactericidal activity of the resulting AgNPs on the Gram-positive and Gram-negative bacteria in comparison to the A. tribuloides root extract. Considering the anti-inflammatory activity, the greenly synthesized AgNPs showed a stranger effect than the A. tribuloides root extract (82% versus 69% at 500 μg/mL). Generally, the AgNPs that were fabricated by using the A. tribuloides root extract had appropriate antioxidant, antibacterial, and anti-inflammatory activities and, therefore, can be considered as a promising candidate for various biomedical applications.


2014 ◽  
Vol 1015 ◽  
pp. 480-483
Author(s):  
Men Wu ◽  
Dong Sheng Wang

Silk sericin is used as a biotemplate to redox silver nanoparticles in situ at room temperature. Silk sericin provides multiple functions in the whole reaction system, serving as the reducing agent of Ag+, and the dispersing and stabilizing agent of the resulted silver nanoparticles. The effect of the concentration of sericin on size and shape of the reduced silver nanoparticles is studied. UV-vis spectra and TEM are used to detected the characteristic plasmon and the appearance of the obtained silver nanoparticles.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5444
Author(s):  
Lukasz Marciniak ◽  
Martyna Nowak ◽  
Anna Trojanowska ◽  
Bartosz Tylkowski ◽  
Renata Jastrzab

In colloidal methods, the morphology of nanoparticles (size and shape) as well as their stability can be controlled by changing the concentration of the substrate, stabilizer, adding inorganic salts, changing the reducer/substrate molar ratio, and changing the pH and reaction time. The synthesis of silver nanoparticles was carried out according to the modified Lee and Meisel method in a wide pH range (from 2.0 to 11.0) using citric acid and malic acid, without adding any additives or stabilizers. Keeping the same reaction conditions as the concentration of acid and silver ions, temperature, and heating time, it was possible to determine the relationship between the reaction pH, the type of acid, and the size of the silver nanoparticles formed. Obtained colloids were analyzed by UV-Vis spectroscopy and investigated by means of Transmission Electron Microscope (TEM). The study showed that the colloids reduced with citric acid and malic acid are stable over time for a minimum of seven weeks. We observed that reactions occurred for citric acid from pH 6.0 to 11.0 and for malic acid from pH 7.0 to 11.0. The average size of the quasi-spherical nanoparticles changed with pH due to the increase of reaction rate.


2021 ◽  
Author(s):  
Tanmoy Dutta ◽  
Swapan Kumar Chowdhury ◽  
Narendra Nath Ghosh ◽  
Mahuya Das ◽  
Asoke P. Chattopadhyay ◽  
...  

Abstract The present study reports a novel, one-pot, cost-effective, green synthesis route of silver nanoparticles (AgNPs) from the fruit extract of Glycosmis pentaphylla (FGP). The UV–vis spectroscopy (UV-Vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM) studies confirmed that the synthesis produces stable, monodispersed AgNPs with an average size of 17 nm. Theoretical simulation using density functional theory (DFT) established that among the different compounds of FGP, arborine is mainly responsible for the stabilization of AgNPs with a binding energy of 58.45 kJ/mol. Synthesized AgNPs showed strong antifungal and antibacterial activity. The synergistic study of AgNPs with fungicide Bavistin and antibiotic Streptomycin produced remarkable morphological abnormalities of A. alternata as observed under the light microscope. Hence, the AgNPs synthesis approach is a progressive step towards various applications to soon control crop and human pathogens.


Author(s):  
Fereshteh Valipour ◽  
Majid Esmhosseini ◽  
Kamelia Nejati ◽  
Hasan Kianfar ◽  
Ardalan Pasdaran ◽  
...  

In recent study, we report the synthesis and antibacterial activity of silver nanoparticles embedded in smart poly(N-isopropylacrylamide)-based hydrogel networks. A series of thermosensitive poly(N-isopropylacrylamide-methacrylic acid-hydroxyethyl methacrylate) [P(NIPAAm-MAA-HEM)] with various cross-linking ratio have been obtained by cross-linking free radical polymerization of N-isopropylacrylamide (NIPAAm), methacrylic acid (MAA), and hydroxyethyl methacrylate (HEM) in the presence of triethyleneglycol dimethacrylate (TEGDMA) as cross-linker. Highly stable and uniformly distributed silver nanoparticles have been obtained with hydrogel networks via in situ reduction of silver nitrate (AgNO3) using sodium borohydride (NaBH4) as reducing agent. The formation of silver nanoparticles has been confirmed with ultraviolet visible (UV–Vis) spectroscopy. Scanning electron microscopy (SEM) results demonstrated that employed hydrogels have regulated the silver nanoparticles size to 50–150 nm. The preliminary antibacterial activity performed to these hydrogel–silver nanocomposites.


Author(s):  
Md. Abdullah Al Masud ◽  
Hamid Shaikh ◽  
Md. Shamsul Alam ◽  
M. Minnatul Karim ◽  
M. Abdul Momin ◽  
...  

Abstract Background The green synthesis strategy of metallic nanoparticles (NPs) has become popular due to being environmentally friendly. Stable silver nanoparticles (AgNPs) have been synthesized by natural products such as starch, soy protein, various extract of leaves, barks, and roots functioning both as reducing and stabilizing agents. Likewise, silk sericin (SS) is a globular protein discarded in the silk factory might be used for NP synthesis. In this research, we focus on the green synthesis and stabilization of AgNPs by SS as well as assessment of their antibacterial activities against some drug-resistant pathogen. Results SS was extracted from Bombyx mori silkworm cocoons in an aqueous medium. 17 w/w% of dry sericin powder with respect to the cocoon’s weight was obtained by freeze-drying. Furthermore, AgNPs conjugated to sericin, i.e., SS-capped silver nanoparticles (SS-AgNPs) were synthesized by easy, cost-effective, and environment-friendly methods. The synthesized SS-AgNPs were characterized by UV-visible spectroscopy, Fourier-transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction measurement. It has been found from the absorbance of UV-visible spectroscopy that a higher percent of SS-AgNPs was obtained at a higher concentration of silver nitrate solution. FTIR-ATR spectra showed that the carboxylate groups obtained from silk sericin act as a reducing agent for the synthesis of silver nanoparticles, while NH2+ and COO− act as a stabilizer of AgNPs. The X-ray diffractogram of SS-AgNPs was quite different from AgNO3 and sericin due to a change in the crystal structure. The diameter of AgNPs was around 20–70 nm observed using TEM. The synthesized SS-AgNPs exhibited strong antibacterial activity against multidrug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 20μg/mL. Conclusions This study encourages the use of Bombyx mori for the ecofriendly synthesis of SS-AgNPs to control multidrug-resistant microorganisms.


RSC Advances ◽  
2021 ◽  
Vol 11 (24) ◽  
pp. 14624-14631
Author(s):  
Pablo Eduardo Cardoso-Avila ◽  
Rita Patakfalvi ◽  
Carlos Rodríguez-Pedroza ◽  
Xochitl Aparicio-Fernández ◽  
Sofía Loza-Cornejo ◽  
...  

Gold and silver nanoparticles were synthesized at room temperature using an aqueous extract from dried rosehips acting as reducing and capping agents with no other chemicals involved.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4041
Author(s):  
Adriana Cecilia Csakvari ◽  
Cristian Moisa ◽  
Dana G. Radu ◽  
Leonard M. Olariu ◽  
Andreea I. Lupitu ◽  
...  

Cannabis sativa L. (hemp) is a plant used in the textile industry and green building material industry, as well as for the phytoremediation of soil, medical treatments, and supplementary food products. The synergistic effect of terpenes, flavonoids, and cannabinoids in hemp extracts may mediate the biogenic synthesis of metal nanoparticles. In this study, the chemical composition of aqueous leaf extracts of three varieties of Romanian hemp (two monoecious, and one dioecious) have been determined by Fourier-Transformed Infrared spectroscopy (FT-IR), high-performance liquid chromatography, and mass spectrometry (UHPLC-DAD-MS). Then, their capability to mediate the green synthesis of silver nanoparticles (AgNPs) and their pottential antibacterial applications were evaluated. The average antioxidant capacity of the extracts had 18.4 ± 3.9% inhibition determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 78.2 ± 4.1% determined by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS™) assays. The total polyphenolic content of the extracts was 1642 ± 32 mg gallic acid equivalent (GAE) L−1. After this, these extracts were reacted with an aqueous solution of AgNO3 resulting in AgNPs, which were characterized by UV−VIS spectroscopy, FT-IR, scanning electron microscopy (SEM-EDX), and dynamic light scattering (DLS). The results demonstrated obtaining spherical, stable AgNPs with a diameter of less than 69 nm and an absorbance peak at 435 nm. The mixture of extracts and AgNPs showed a superior antioxidant capacity of 2.3 ± 0.4% inhibition determined by the DPPH• assay, 88.5 ± 0.9% inhibition as determined by the ABTS•+ assay, and a good antibacterial activity against several human pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas fluorescens, and Staphylococcus aureus.


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